입술 돌출을 동반한 골격성 II급 부정교합 환자에서 입술 반응을 고려한 치료계획 수립 및 안모 개선 치험례

Treatment Considering Lip Response in Skeletal Class II Malocclusion with Lip Protrusion

As interest in soft tissue esthetics increases, the soft tissue paradigm is becoming the mainstream. In the soft tissue paradigm, treatment planning for not only the hard tissue but also the soft tissue relationships through a thorough soft tissue analysis is essential. In particular, the lips are closely related to the position of the incisors. The causes of the incompetent and protruded lips, which are the main factors of unattractive appearance, vary but are mainly due to the protrusion of incisors. At this point, retraction of the incisors can be planned as a treatment. One of the factors that helps predicting the lip response during maxillary incisor retraction is ‘upper lip strain’ proposed by Holdaway. In this case of a skeletal class II malocclusion patient with lip protrusion and incompetent lips, the treatment plan was established by predicting the lip response that would occur during incisor retraction by considering the ‘upper lip strain’. With extraction and skeletal anchorage, improvement of the lip position was achieved as well we the chin advancement by counterclockwise rotation of the mandible. Based on this, a good occlusal relationship and esthetical facial appearance was obtained. However, the unpredictability and individual variability of soft tissues is the limitation in soft tissue analysis.